#include <QApplication>
 #include <QFont>
 #include <QGridLayout>
 #include <QHBoxLayout>
 #include <QPushButton>
 #include <QVBoxLayout>

 #include "cannonfield.h"
 #include "lcdrange.h"

 class MyWidget : public QWidget
 {
 public:
     MyWidget(QWidget *parent = 0);
 };

 MyWidget::MyWidget(QWidget *parent)
     : QWidget(parent)
 {
     QPushButton *quit = new QPushButton(tr("&Quit"));
     quit->setFont(QFont("Times", 18, QFont::Bold));

     connect(quit, SIGNAL(clicked()), qApp, SLOT(quit()));

     LCDRange *angle = new LCDRange(tr("ANGLE"));
     angle->setRange(5, 70);

     LCDRange *force = new LCDRange(tr("FORCE"));
     force->setRange(10, 50);

     CannonField *cannonField = new CannonField;

     connect(angle, SIGNAL(valueChanged(int)),
             cannonField, SLOT(setAngle(int)));
     connect(cannonField, SIGNAL(angleChanged(int)),
             angle, SLOT(setValue(int)));

     connect(force, SIGNAL(valueChanged(int)),
             cannonField, SLOT(setForce(int)));
     connect(cannonField, SIGNAL(forceChanged(int)),
             force, SLOT(setValue(int)));

     QPushButton *shoot = new QPushButton(tr("&Shoot"));
     shoot->setFont(QFont("Times", 18, QFont::Bold));

     connect(shoot, SIGNAL(clicked()), cannonField, SLOT(shoot()));

     QHBoxLayout *topLayout = new QHBoxLayout;
     topLayout->addWidget(shoot);
     topLayout->addStretch(1);

     QVBoxLayout *leftLayout = new QVBoxLayout;
     leftLayout->addWidget(angle);
     leftLayout->addWidget(force);

     QGridLayout *gridLayout = new QGridLayout;
     gridLayout->addWidget(quit, 0, 0);
     gridLayout->addLayout(topLayout, 0, 1);
     gridLayout->addLayout(leftLayout, 1, 0);
     gridLayout->addWidget(cannonField, 1, 1, 2, 1);
     gridLayout->setColumnStretch(1, 10);
     setLayout(gridLayout);

     angle->setValue(60);
     force->setValue(25);
     angle->setFocus();
 }

 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     MyWidget widget;
     widget.setGeometry(100, 100, 500, 355);
     widget.show();
     return app.exec();
 }